Fixing STR #2901, wrongly escaping the formatting character code in Fl_Browser.

FL/Fl_Browser.H

@@ -212,7 +212,7 @@ public:
     and used to modify how the rest of the line is printed:
     
     \li <tt>'\@.'</tt> Print rest of line, don't look for more '\@' signs
-    \li <tt>'\@\@'</tt> Print rest of line starting with '\@'
+    \li <tt>'\@\@'</tt> Doubling the format character prints the format character once, followed by the rest of line
     \li <tt>'\@l'</tt> Use a LARGE (24 point) font
     \li <tt>'\@m'</tt> Use a medium large (18 point) font
     \li <tt>'\@s'</tt> Use a <SMALL>small</SMALL> (11 point) font

src/Fl_Browser.cxx

@@ -378,8 +378,7 @@ int Fl_Browser::item_height(void *item) const {
       Fl_Font font = textfont(); // default font
       int tsize = textsize();    // default size
       if ( format_char() ) {     // can be NULL
-	while (*str==format_char()) {
-	  str++;
+	while (*str==format_char() && *str++ && *str!=format_char()) {
 	  switch (*str++) {
 	  case 'l': case 'L': tsize = 24; break;
 	  case 'm': case 'M': tsize = 18; break;
@@ -391,7 +390,6 @@ int Fl_Browser::item_height(void *item) const {
 	  case 'C': while (isdigit(*str & 255)) str++; break; // skip a color number
 	  case 'F': font = (Fl_Font)strtol(str,&str,10); break;
 	  case 'S': tsize = strtol(str,&str,10); break;
-	  case 0: case '@': str--;
 	  case '.': goto END_FORMAT;
 	  }
 	}
@@ -458,9 +456,6 @@ int Fl_Browser::item_width(void *item) const {
       case '.':
 	done = 1;
 	break;
-      case '@':
-	str--;
-	done = 1;
       }
 
     if (done)
@@ -578,8 +573,6 @@ void Fl_Browser::item_draw(void* item, int X, int Y, int W, int H) const {
 	  break;
 	case '.':
 	  goto BREAK;
-	case '@':
-	  str--; goto BREAK;
 	}
       }
     }

test/browser.cxx

@@ -45,6 +45,9 @@ That was a blank line above this.
 @C2Green
 @C4Blue
 
+@@ start line with '@'
+@.@ alternative start line with '@'
+
 	You should try different browser types:
 	Fl_Browser
 	Fl_Select_Browser
@@ -164,6 +167,7 @@ int main(int argc, char **argv) {
   browser->callback(b_cb);
   // browser->scrollbar_right();
   //browser->has_scrollbar(Fl_Browser::BOTH_ALWAYS);
+  //browser->format_char('#');
   if (!browser->load(fname)) {
     int done = 0;
 #ifdef _MSC_VER